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Asif A, Chen JS, Hussain B, Hsu GJ, Rathod J, Huang SW, Wu CC, Hsu BM. The escalating threat of human-associated infectious bacteria in surface aquatic resources: Insights into prevalence, antibiotic resistance, survival mechanisms, detection, and prevention strategies. JOURNAL OF CONTAMINANT HYDROLOGY 2024; 265:104371. [PMID: 38851127 DOI: 10.1016/j.jconhyd.2024.104371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 05/24/2024] [Accepted: 05/30/2024] [Indexed: 06/10/2024]
Abstract
Anthropogenic activities and climate change profoundly impact water quality, leading to a concerning increase in the prevalence and abundance of bacterial pathogens across diverse aquatic environments. This rise has resulted in a growing challenge concerning the safety of water sources, particularly surface waters and marine environments. This comprehensive review delves into the multifaceted challenges presented by bacterial pathogens, emphasizing threads to human health within ground and surface waters, including marine ecosystems. The exploration encompasses the intricate survival mechanisms employed by bacterial pathogens and the proliferation of antimicrobial resistance, largely driven by human-generated antibiotic contamination in aquatic systems. The review further addresses prevalent pathogenic bacteria, elucidating associated risk factors, exploring their eco-physiology, and discussing the production of potent toxins. The spectrum of detection techniques, ranging from conventional to cutting-edge molecular approaches, is thoroughly examined to underscore their significance in identifying and understanding waterborne bacterial pathogens. A critical aspect highlighted in this review is the imperative for real-time monitoring of biomarkers associated with waterborne bacterial pathogens. This monitoring serves as an early warning system, facilitating the swift implementation of action plans to preserve and protect global water resources. In conclusion, this comprehensive review provides fresh insights and perspectives, emphasizing the paramount importance of preserving the quality of aquatic resources to safeguard human health on a global scale.
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Affiliation(s)
- Aslia Asif
- Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi County, Taiwan; Doctoral Program in Science, Technology, Environment, and Mathematics, National Chung Cheng University, Chiayi County, Taiwan
| | - Jung-Sheng Chen
- Department of Medical Research, E-Da Hospital, I-Shou University, Kaohsiung, Taiwan
| | - Bashir Hussain
- Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi County, Taiwan
| | - Gwo-Jong Hsu
- Division of Infectious Disease and Department of Internal Medicine, Chiayi Christian Hospital, Chiayi, Taiwan
| | - Jagat Rathod
- Department of Environmental Biotechnology, Gujarat Biotechnology University, Near Gujarat International Finance and Tec (GIFT)-City, Gandhinagar 382355, Gujarat, India
| | - Shih-Wei Huang
- Institute of Environmental Toxin and Emerging Contaminant, Cheng Shiu University, Kaohsiung, Taiwan; Center for Environmental Toxin and Emerging Contaminant Research, Cheng Shiu University, Kaohsiung, Taiwan
| | - Chin-Chia Wu
- Division of Colorectal Surgery, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan
| | - Bing-Mu Hsu
- Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi County, Taiwan.
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2
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Ibangha IAI, Digwo DC, Ozochi CA, Enebe MC, Ateba CN, Chigor VN. A meta-analysis on the distribution of pathogenic Vibrio species in water sources and wastewater in Africa. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 881:163332. [PMID: 37028683 DOI: 10.1016/j.scitotenv.2023.163332] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 03/31/2023] [Accepted: 04/02/2023] [Indexed: 06/01/2023]
Abstract
Vibrio species are waterborne ubiquitous organisms capable of causing diseases in humans and animals and the occurrence of infections caused by pathogenic Vibrio species among humans have increased globally. This reemergence is attributed to environmental impacts such as global warming and pollution. Africa is most vulnerable to waterborne infections caused by these pathogens because of lack of good water stewardship and management. This study was carried out to provide an in-depth inquiry into the occurrence of pathogenic Vibrio species in water sources and wastewater across Africa. In this regard, a systematic review and meta-analysis was conducted by searching five databases: PubMed, ScienceDirect, Google Scholar, Springer Search and African Journals Online (AJOL). The search yielded 70 articles on pathogenic Vibrio species presence in African aquatic environments that fit our inclusion criteria. Based on the random effects model, the pooled prevalence of pathogenic Vibrio species in various water sources in Africa was 37.6 % (95 % CI: 27.7-48.0). Eighteen countries were represented by the systematically assessed studies and their nationwide prevalence in descending order was: Nigeria (79.82 %), Egypt (47.5 %), Tanzania (45.8 %), Morocco (44.8), South Africa (40.6 %), Uganda (32.1 %), Cameroon (24.5 %), Burkina Faso (18.9 %) and Ghana (5.9 %). Furthermore, 8 pathogenic Vibrio species were identified across water bodies in Africa with the highest detection for V. cholerae (59.5 %), followed by V. parahaemolyticus (10.4 %), V.alginolyticus (9.8 %), V. vulnificus (8.5 %), V. fluvialis (6.6 %), V. mimicus (4.6 %), V. harveyi (0.5 %) and V. metschnikovii (0.1 %). Evidently, pathogenic Vibrio species occurrence in these water sources especially freshwater corroborates the continuous outbreaks observed in Africa. Therefore, there is an urgent need for proactive measures and continuous monitoring of water sources used for various purposes across Africa and proper treatment of wastewater before discharge into water bodies.
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Affiliation(s)
- Ini-Abasi I Ibangha
- Water and Public Health Research Group (WPHRG), Department of Microbiology, Faculty of Biological Sciences, University of Nigeria, Nsukka, Enugu State, Nigeria
| | - Daniel C Digwo
- Water and Public Health Research Group (WPHRG), Department of Microbiology, Faculty of Biological Sciences, University of Nigeria, Nsukka, Enugu State, Nigeria
| | - Chizoba A Ozochi
- Water and Public Health Research Group (WPHRG), Department of Microbiology, Faculty of Biological Sciences, University of Nigeria, Nsukka, Enugu State, Nigeria
| | - Matthew C Enebe
- Water and Public Health Research Group (WPHRG), Department of Microbiology, Faculty of Biological Sciences, University of Nigeria, Nsukka, Enugu State, Nigeria; Food Security and Safety Niche Area, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho 2735, South Africa
| | - Collins N Ateba
- Water and Public Health Research Group (WPHRG), Department of Microbiology, Faculty of Biological Sciences, University of Nigeria, Nsukka, Enugu State, Nigeria; Food Security and Safety Niche Area, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho 2735, South Africa
| | - Vincent N Chigor
- Water and Public Health Research Group (WPHRG), Department of Microbiology, Faculty of Biological Sciences, University of Nigeria, Nsukka, Enugu State, Nigeria.
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Fox BG, Thorn RMS, Dutta TK, Bowes MJ, Read DS, Reynolds DM. A case study: The deployment of a novel in situ fluorimeter for monitoring biological contamination within the urban surface waters of Kolkata, India. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 842:156848. [PMID: 35750190 DOI: 10.1016/j.scitotenv.2022.156848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 06/15/2022] [Accepted: 06/16/2022] [Indexed: 06/15/2023]
Abstract
The quality and health of many of our vital freshwater systems are poor. To tackle this with ever increasing pressures from anthropogenic and climatic changes, we must improve water quality monitoring and devise and implement more appropriate water quality parameters. Recent research has highlighted the potential for Peak T fluorescence (tryptophan-like fluorescence, TLF) to monitor microbial activity in aquatic systems. The VLux TPro (Chelsea Technologies Ltd., UK), an in situ real-time fluorimeter, was deployed in different urban freshwater bodies within Kolkata (West Bengal, India) during March 2019. This study is the first to apply this technology in surface waters within a densely populated urban area. Spot-sampling was also undertaken at 13 sampling locations enabling physicochemical analysis, bacterial enumeration and determination of nutrient (nitrate and phosphate) concentrations. This case study has demonstrated the ability of an in situ fluorimeter, VLux TPro, to successfully identify both biological contamination events and potential elevated microbial activity, related to nutrient loading, in complex surface freshwaters, without the need for expensive and time-consuming laboratory analysis.
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Affiliation(s)
- B G Fox
- Centre for Research in Biosciences, University of the West of England (UWE), Bristol, Frenchay Campus, Bristol BS16 1QY, UK
| | - R M S Thorn
- Centre for Research in Biosciences, University of the West of England (UWE), Bristol, Frenchay Campus, Bristol BS16 1QY, UK
| | - T K Dutta
- Department of Microbiology, Bose Institute P-1/12 C.I.T. Scheme VII-M, Centenary Campus, Kolkata 700054, India
| | - M J Bowes
- UK Centre for Ecology & Hydrology (UKCEH), Benson Lane, Crowmarsh Gifford, Wallingford OX10 8BB, UK
| | - D S Read
- UK Centre for Ecology & Hydrology (UKCEH), Benson Lane, Crowmarsh Gifford, Wallingford OX10 8BB, UK
| | - D M Reynolds
- Centre for Research in Biosciences, University of the West of England (UWE), Bristol, Frenchay Campus, Bristol BS16 1QY, UK.
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Halla FF, Massawa SM, Joseph EK, Acharya K, Sabai SM, Mgana SM, Werner D. Attenuation of bacterial hazard indicators in the subsurface of an informal settlement and their application in quantitative microbial risk assessment. ENVIRONMENT INTERNATIONAL 2022; 167:107429. [PMID: 35914337 DOI: 10.1016/j.envint.2022.107429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 07/20/2022] [Accepted: 07/21/2022] [Indexed: 06/15/2023]
Abstract
Pit latrines provide essential onsite sanitation services to over a billion people, but there are concerns about their role in infectious disease transmission, and impacts on groundwater resources. We conducted fieldwork in an informal settlement in Dar es Salaam, where cholera is endemic. We combined plate counting with portable MinION sequencing and quantitative polymerase chain reaction (qPCR) methods for characterization of bacteria in pit latrine sludge, leachate, shallow and deep groundwater resources. Pit latrine sludge was characterized by log10 marker gene concentrations per 100 mL of 11.2 ± 0.2, 9.9 ± 0.9, 6.0 ± 0.3, and 4.4 ± 0.8, for total bacteria (16S rRNA), E. coli (rodA), human-host-associated Bacteroides (HF183), and Vibrio cholerae (ompW), respectively. The ompW gene observations suggested 5 % asymptomatic Vibrio cholerae carriers amongst pit latrine users. Pit leachate percolation through one-meter-thick sand beds attenuated bacterial hazard indicators by 1 to 4 log10 units. But first-order removal rates derived from these data substantially overestimated the longer-range hazard attenuation in the sand aquifers. Cooccurrence of human sewage marker gene HF183 in all shallow groundwater samples testing positive for ompW genes demonstrated the human origin of Vibrio cholerae hazards in the subsurface. All borehole water samples tested negative for ompW and HF183 genes, but 16S rRNA gene sequencing data suggested ingress of faecal pollution into boreholes at the peak of the "long rainy season". Quantitative microbial risk assessment (QMRA) predicted a gastrointestinal disease burden of 0.05 DALY per person per year for the community, well above WHO targets of 10-4-10-6 DALY for disease related to drinking water.
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Affiliation(s)
- Franella Francos Halla
- Department of Environmental Engineering, School of Environmental Science and Technology, Ardhi University, Dar es Salaam, Tanzania
| | - Said Maneno Massawa
- Department of Environmental Engineering, School of Environmental Science and Technology, Ardhi University, Dar es Salaam, Tanzania
| | - Elihaika Kengalo Joseph
- Department of Environmental Engineering, School of Environmental Science and Technology, Ardhi University, Dar es Salaam, Tanzania
| | - Kishor Acharya
- School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Shadrack Mwita Sabai
- Department of Environmental Engineering, School of Environmental Science and Technology, Ardhi University, Dar es Salaam, Tanzania
| | - Shaaban Mrisho Mgana
- Department of Environmental Engineering, School of Environmental Science and Technology, Ardhi University, Dar es Salaam, Tanzania.
| | - David Werner
- School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, UK.
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The Prevalence of Arcobacteraceae in Aquatic Environments: A Systematic Review and Meta-Analysis. Pathogens 2022; 11:pathogens11020244. [PMID: 35215187 PMCID: PMC8880612 DOI: 10.3390/pathogens11020244] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 01/31/2022] [Accepted: 02/10/2022] [Indexed: 11/17/2022] Open
Abstract
Members of the family Arcobacteraceae are distributed widely in aquatic environments, and some of its species have been associated with human and animal illness. However, information about the diversity and distribution of Arcobacteraceae in different water bodies is still limited. In order to better characterize the health risk posed by members in the family Arcobacteraceae, a systematic review and meta-analysis-based method was used to investigate the prevalence of Arcobacteraceae species in aquatic environments based on available data published worldwide. The database search was performed using related keywords and considering studies up to February 2021. The pooled prevalence in aquatic environments was 69.2%, ranging from 0.6 to 99.9%. These bacteria have a wide geographical distribution, being found in diverse aquatic environments with the highest prevalence found in raw sewage and wastewater treatment plants (WWTP), followed by seawater, surface water, ground water, processing water from food processing plants and water for human consumption. Assessing the effectiveness of treatments in WWTP in eliminating this contamination, it was found that the wastewater treatment may not be efficient in the removal of Arcobacteraceae. Among the analyzed Arcobacteraceae species, Al. butzleri was the most frequently found species. These results highlight the high prevalence and distribution of Arcobacteraceae in different aquatic environments, suggesting a risk to human health. Further, it exposes the importance of identifying and managing the sources of contamination and taking preventive actions to reduce the burden of members of the Arcobacteraceae family.
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Aondoakaa SC, Jewitt S. Effects of seasonality on access to improved water in Benue State, Nigeria. ENVIRONMENTAL MONITORING AND ASSESSMENT 2021; 194:40. [PMID: 34935063 DOI: 10.1007/s10661-021-09454-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Accepted: 09/07/2021] [Indexed: 06/14/2023]
Abstract
Many people switch sources of drinking water and sanitation between seasons, yet such shifts are not reflected in the reporting of access to improved water and sanitation services by the Joint Monitoring Programme (JMP). Drawing on quantitative and qualitative data collected from urban and rural sites in dry and rainy seasons in Benue state, Nigeria, this study highlights the importance of seasonal variations in water access and quality. Water testing showed that water sources had higher levels of contamination with coliforms, nitrate and chloride in the dry season than the wet season. The contamination of water from these pollutants is above WHO standards and believed to come mainly from pit latrines. Semi-structured interviews revealed that many people who use improved water and sanitation facilities in the rainy season sometimes switch to poorer quality unimproved sources in the dry season. Travel times for collecting water as well as waiting times also significantly increased in the dry season. It is recommended that this important seasonality element is factored into JMP data collection and reporting.
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Affiliation(s)
- Stephen Chiahemba Aondoakaa
- School of Geography, University of Nottingham, Nottingham, UK.
- Department of Geography and Environmental Management, University of Abuja, Abuja, Nigeria.
| | - Sarah Jewitt
- School of Geography, University of Nottingham, Nottingham, UK
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7
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Espira L, Aung T, Han K, Jagger P, Eisenberg JNS. Determinants of Pathogen Contamination of the Environment in the Greater Yangon Area, Myanmar. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:16465-16476. [PMID: 34792323 DOI: 10.1021/acs.est.1c02887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Recent results from water, sanitation, and hygiene interventions highlight the need to better understand environmental influences on enteropathogen transmission. We quantified a range of viral, bacterial, and protozoal pathogens and one indicator, Enterococcus faecalis in soil and water from urban and rural sites in and around Yangon, Myanmar. We found that environmental characteristics associated with contamination differed by pathogens and substrates. In soil, bacterial pathogen gene counts were associated with elevation and drainage ditches (compared to stagnant water) (RR = 0.96, 95% CI 0.93, 0.99 and RR = 1.70, 95% CI 1.18, 2.45, respectively), while viral gene counts were associated with the presence of sanitation facilities within 50 m of the collection point (RR = 3.99, 95% CI 1.12, 14.24). In water, E. faecalis, total pathogen, and bacterial pathogen gene counts were associated with drainage ditches (RR = 1.86, 95% CI 1.27, 2.72, RR = 1.38 95% CI 1.09, 1.74, and RR = 1.38 95% CI 1.07, 1.77, respectively). E. faecalis, total pathogen, bacterial pathogen, and viral gene counts were associated with the presence of uncollected garbage within 50 m of the collection point (RR = 1.57, 95% CI 1.00, 2.47, RR = 1.52, 95% CI 1.16, 2.00, RR = 1.52, 95% CI 1.13, 2.06, and RR = 1.75, 95% CI 1.17, 2.61 respectively). Measuring the environment provides added specificity toward identifying important environmental pathways that require mitigation.
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Affiliation(s)
- Leon Espira
- Department of Epidemiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Ther Aung
- Carolina Population Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27516, United States
| | - Khin Han
- Department of Geography, West Yangon University, Yangon 13393, Myanmar
| | - Pamela Jagger
- School for Environment and Sustainability, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Joseph N S Eisenberg
- Department of Epidemiology, University of Michigan, Ann Arbor, Michigan 48109, United States
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8
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Sorensen JPR, Nayebare J, Carr AF, Lyness R, Campos LC, Ciric L, Goodall T, Kulabako R, Curran CMR, MacDonald AM, Owor M, Read DS, Taylor RG. In-situ fluorescence spectroscopy is a more rapid and resilient indicator of faecal contamination risk in drinking water than faecal indicator organisms. WATER RESEARCH 2021; 206:117734. [PMID: 34655933 DOI: 10.1016/j.watres.2021.117734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 09/24/2021] [Accepted: 09/29/2021] [Indexed: 06/13/2023]
Abstract
Faecal indicator organisms (FIOs) are limited in their ability to protect public health from the microbial contamination of drinking water because of their transience and time required to deliver a result. We evaluated alternative rapid, and potentially more resilient, approaches against a benchmark FIO of thermotolerant coliforms (TTCs) to characterise faecal contamination over 14 months at 40 groundwater sources in a Ugandan town. Rapid approaches included: in-situ tryptophan-like fluorescence (TLF), humic-like fluorescence (HLF), turbidity; sanitary inspections; and total bacterial cells by flow cytometry. TTCs varied widely in six sampling visits: a third of sources tested both positive and negative, 50% of sources had a range of at least 720 cfu/100 mL, and a two-day heavy rainfall event increased median TTCs five-fold. Using source medians, TLF was the best predictor in logistic regression models of TTCs ≥10 cfu/100 mL (AUC 0.88) and best correlated to TTC enumeration (ρs 0.81), with HLF performing similarly. Relationships between TLF or HLF and TTCs were stronger in the wet season than the dry season, when TLF and HLF were instead more associated with total bacterial cells. Source rank-order between sampling rounds was considerably more consistent, according to cross-correlations, using TLF or HLF (min ρs 0.81) than TTCs (min ρs 0.34). Furthermore, dry season TLF and HLF cross-correlated more strongly (ρs 0.68) than dry season TTCs (ρs 0.50) with wet season TTCs, when TTCs were elevated. In-situ TLF or HLF are more rapid and resilient indicators of faecal contamination risk than TTCs.
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Affiliation(s)
- James P R Sorensen
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB, United Kingdom of Great Britain and Northern Ireland UK; Department of Geography, University College London, London WC1E 6BT, United Kingdom of Great Britain and Northern Ireland UK.
| | - Jacintha Nayebare
- Department of Geology and Petroleum Studies, Makerere University, Uganda
| | - Andrew F Carr
- Department of Geography, University College London, London WC1E 6BT, United Kingdom of Great Britain and Northern Ireland UK
| | - Robert Lyness
- Department of Civil, Environmental & Geomatic Engineering, University College London, London WC1E 6BT, United Kingdom of Great Britain and Northern Ireland UK
| | - Luiza C Campos
- Department of Civil, Environmental & Geomatic Engineering, University College London, London WC1E 6BT, United Kingdom of Great Britain and Northern Ireland UK
| | - Lena Ciric
- Department of Civil, Environmental & Geomatic Engineering, University College London, London WC1E 6BT, United Kingdom of Great Britain and Northern Ireland UK
| | - Timothy Goodall
- UK Centre for Ecology & Hydrology (UKCEH), Maclean Building, Wallingford, OX10 8BB, United Kingdom of Great Britain and Northern Ireland UK
| | - Robinah Kulabako
- Department of Civil and Environmental Engineering, Makerere University, Uganda
| | - Catherine M Rushworth Curran
- Catherine M Rushworth Curran Ltd., 27 Silverhall Street, Isleworth, TW7 6RF, United Kingdom of Great Britain and Northern Ireland UK
| | - Alan M MacDonald
- British Geological Survey, Lyell Centre, Research Avenue South, Edinburgh EH14 4AP, United Kingdom of Great Britain and Northern Ireland UK
| | - Michael Owor
- Department of Geology and Petroleum Studies, Makerere University, Uganda
| | - Daniel S Read
- UK Centre for Ecology & Hydrology (UKCEH), Maclean Building, Wallingford, OX10 8BB, United Kingdom of Great Britain and Northern Ireland UK
| | - Richard G Taylor
- Department of Geography, University College London, London WC1E 6BT, United Kingdom of Great Britain and Northern Ireland UK
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9
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Bell RL, Kase JA, Harrison LM, Balan KV, Babu U, Chen Y, Macarisin D, Kwon HJ, Zheng J, Stevens EL, Meng J, Brown EW. The Persistence of Bacterial Pathogens in Surface Water and Its Impact on Global Food Safety. Pathogens 2021; 10:1391. [PMID: 34832547 PMCID: PMC8617848 DOI: 10.3390/pathogens10111391] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 10/15/2021] [Accepted: 10/19/2021] [Indexed: 11/17/2022] Open
Abstract
Water is vital to agriculture. It is essential that the water used for the production of fresh produce commodities be safe. Microbial pathogens are able to survive for extended periods of time in water. It is critical to understand their biology and ecology in this ecosystem in order to develop better mitigation strategies for farmers who grow these food crops. In this review the prevalence, persistence and ecology of four major foodborne pathogens, Shiga toxin-producing Escherichia coli (STEC), Salmonella, Campylobacter and closely related Arcobacter, and Listeria monocytogenes, in water are discussed. These pathogens have been linked to fresh produce outbreaks, some with devastating consequences, where, in a few cases, the contamination event has been traced to water used for crop production or post-harvest activities. In addition, antimicrobial resistance, methods improvements, including the role of genomics in aiding in the understanding of these pathogens, are discussed. Finally, global initiatives to improve our knowledge base of these pathogens around the world are touched upon.
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Affiliation(s)
- Rebecca L. Bell
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA; (J.A.K.); (Y.C.); (D.M.); (H.J.K.); (J.Z.); (E.W.B.)
| | - Julie A. Kase
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA; (J.A.K.); (Y.C.); (D.M.); (H.J.K.); (J.Z.); (E.W.B.)
| | - Lisa M. Harrison
- Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, Food and Drug Administration, Laurel, MD 20708, USA; (L.M.H.); (K.V.B.); (U.B.)
| | - Kannan V. Balan
- Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, Food and Drug Administration, Laurel, MD 20708, USA; (L.M.H.); (K.V.B.); (U.B.)
| | - Uma Babu
- Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition, Food and Drug Administration, Laurel, MD 20708, USA; (L.M.H.); (K.V.B.); (U.B.)
| | - Yi Chen
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA; (J.A.K.); (Y.C.); (D.M.); (H.J.K.); (J.Z.); (E.W.B.)
| | - Dumitru Macarisin
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA; (J.A.K.); (Y.C.); (D.M.); (H.J.K.); (J.Z.); (E.W.B.)
| | - Hee Jin Kwon
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA; (J.A.K.); (Y.C.); (D.M.); (H.J.K.); (J.Z.); (E.W.B.)
| | - Jie Zheng
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA; (J.A.K.); (Y.C.); (D.M.); (H.J.K.); (J.Z.); (E.W.B.)
| | - Eric L. Stevens
- Office of the Center Director, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA;
| | - Jianghong Meng
- Joint Institute for Food Safety and Applied Nutrition, Center for Food Safety and Security Systems, University of Maryland, College Park, MD 20742, USA;
| | - Eric W. Brown
- Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA; (J.A.K.); (Y.C.); (D.M.); (H.J.K.); (J.Z.); (E.W.B.)
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10
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Laboratory In-Situ Production of Autochthonous and Allochthonous Fluorescent Organic Matter by Freshwater Bacteria. Microorganisms 2021; 9:microorganisms9081623. [PMID: 34442702 PMCID: PMC8400322 DOI: 10.3390/microorganisms9081623] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/16/2021] [Accepted: 07/26/2021] [Indexed: 11/17/2022] Open
Abstract
This work investigates the origin and range of fluorescent organic matter (FOM) produced in-situ by environmentally sourced freshwater bacteria. Aquatic FOM is an essential component in global carbon cycling and is generally classified as either autochthonous, produced in-situ via microbial processes, or allochthonous, transported into aquatic systems from external sources. We have demonstrated that, within laboratory model systems, environmentally sourced mixed microbial communities and bacterial isolates can produce and/or export FOM associated with both autochthonous and allochthonous material. This study focuses on fluorescence peak B, T, M, C and C+, exploring (1) the cellular nature of FOM produced, (2) FOM exported as extracellular material into the water column and (3) the impact of physical cell lysis on FOM signature. For the laboratory model systems studied, Peak T fluorescence is retained within bacterial cells (>68%), while Peak C fluorescence is mainly observed as extracellular material (>80%). Peak M is identified as both cellular and extracellular FOM, produced by all isolated freshwater microorganisms investigated. The origin of Peak C+ is postulated to originate from functional metabolites associated with specific microorganisms, seen specifically within the Pseudomonas sp. monoculture here. This work challenges the binary classification of FOM as either allochthonous or autochthonous, suggesting that FOM processing and production occurs along a dynamic continuum. Within this study, fluorescence intensity data for the environmental bacteria isolate monocultures are presented as enumeration corrected data, for the first time providing quantitative fluorescence data per bacterial colony forming unit (cfu). From this, we are able to assess the relative contribution of different bacteria to the autochthonous FOM pool and if this material is cellular or extracellular.
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11
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Monitoring Groundwater Use as a Domestic Water Source by Urban Households: Analysis of Data from Lagos State, Nigeria and Sub-Saharan Africa with Implications for Policy and Practice. WATER 2021. [DOI: 10.3390/w13040568] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The fundamental importance of groundwater for urban drinking water supplies in sub-Saharan Africa is increasingly recognised. However, little is known about the trends in urban groundwater development by individual households and its role in securing safely-managed drinking water supplies. Anecdotal evidence indicates a thriving self-supply movement to exploit groundwater in some urban sub-Saharan African settings, but empirical evidence, or analysis of the benefits and drawbacks, remains sparse. Through a detailed analysis of official datasets for Lagos State, Nigeria we examine the crucial role played by groundwater and, specifically, by household self-supply for domestic water provision. We then set this in the context of Nigeria and of sub-Saharan Africa. One of the novelties of this multi-scalar approach is that it provides a granular understanding from large-scale datasets. Our analysis confirms the importance of non-piped water supplies in meeting current and future drinking water demand by households in parts of sub-Saharan Africa and the role played, through self-supply, by groundwater. Our results demonstrate inconsistencies between datasets, and we make recommendations for the future. We argue that a key actor in the provision of drinking water supplies, the individual household, is largely overlooked by officially reported data, with implications for both policy and practice.
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12
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Reaver KM, Levy J, Nyambe I, Hay MC, Mutiti S, Chandipo R, Meiman J. Drinking Water Quality and Provision in Six Low-Income, Peri-Urban Communities of Lusaka, Zambia. GEOHEALTH 2021; 5:e2020GH000283. [PMID: 33392423 PMCID: PMC7770328 DOI: 10.1029/2020gh000283] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 10/13/2020] [Accepted: 11/12/2020] [Indexed: 05/31/2023]
Abstract
Lusaka, Zambia, is a rapidly growing city located on a vulnerable karstic dolomite aquifer that provides most of the city's drinking water. Over 65% of residents live in peri-urban communities with inadequate sanitation leading to widespread groundwater contamination and the spread of waterborne diseases such as cholera. To fill the water service gap, Water Trusts were created: public/private partnerships designed to provide clean water to peri-urban community residents. Water Trusts extract groundwater via boreholes, treat it with chlorine, and distribute it to residents via public kiosks. We investigated the efficacy of drinking water provision to residents in six of Lusaka's peri-urban communities with Water Trusts. Water samples were collected from Water Trust boreholes and kiosks, privately owned boreholes, and shallow wells during four sampling efforts. To assess potential risk to human health, water samples were analyzed for Escherichia coli (E. coli) and nitrate. Shallow wells were significantly more contaminated with E. coli than Water Trust boreholes, kiosks, and private boreholes (Tukey-adjusted p values of 9.9 × 10-6). Shallow wells and private boreholes had significantly higher nitrate-N concentrations (mean of 29.6 mg/L) than the Water Trust boreholes and kiosks (mean of 8.8 mg/L) (p value = 1.1 × 10-4). In 2016, a questionnaire was distributed to Water Trust managers to assess their ability to meet demands. In the six communities studied, Water Trusts served only about 60% of their residents. Water Trusts provide a much safer alternative to shallow wells with respect to nitrate and E. coli, but they struggle to keep pace with growing demand.
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Affiliation(s)
- Kristen M. Reaver
- Institute for the Environment and SustainabilityMiami UniversityOxfordOHUSA
- Now at U.S. Geological Survey Wetland and Aquatic Research CenterGainesvilleFLUSA
| | - Jonathan Levy
- Institute for the Environment and SustainabilityMiami UniversityOxfordOHUSA
| | - Imasiku Nyambe
- University of Zambia Integrated Water Resources Management Centre, Department of Geology, School of MinesUniversity of ZambiaLusakaZambia
| | | | - Sam Mutiti
- Department of Biological and Environmental SciencesGeorgia College and State UniversityMilledgevilleGAUSA
| | - Rodwell Chandipo
- Zambia Environmental Management Agency, InspectorateLusakaZambia
| | - Joseph Meiman
- Cumberland Piedmont Inventory and Monitoring NetworkMammothKYUSA
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13
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Ward JST, Lapworth DJ, Read DS, Pedley S, Banda ST, Monjerezi M, Gwengweya G, MacDonald AM. Tryptophan-like fluorescence as a high-level screening tool for detecting microbial contamination in drinking water. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 750:141284. [PMID: 33182170 DOI: 10.1016/j.scitotenv.2020.141284] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 07/23/2020] [Accepted: 07/25/2020] [Indexed: 06/11/2023]
Abstract
Regular monitoring of drinking water quality is vital to identify contamination of potable water supplies. Testing for microbial contamination is important to prevent transmission of waterborne disease, but establishing and maintaining a water quality monitoring programme requires sustained labour, consumables and resources. In low resource settings such as developing countries, this can prove difficult, but measuring microbial contamination is listed as a requirement of reaching the UN's Sustainable Development Goal 6 for water and sanitation. A nine-month water quality monitoring programme was conducted in rural Malawi to assess the suitability of tryptophan-like fluorescence (TLF), an emerging method for rapidly detecting microbial contamination, as a drinking water quality monitoring tool. TLF data was compared with thermotolerant coliforms (TTCs, E. coli) and inorganic hydrochemical parameters. A large (n = 235) temporal dataset was collected from five groundwater drinking water sources, with samples collected once or twice weekly depending on the season. The results show that TLF can indicate a broader contamination risk but is not as sensitive to short term variability when compared to other faecal indicators. This is likely due to a broad association of TLF with elevated DOC concentrations from a range of different sources. Elevated TLF may indicate preferential conditions for the persistence of TTCs and/or E. coli, but not necessarily a public health risk from microbial contamination. TLF is therefore a more precautionary risk indicator than microbial culturing techniques and could prove useful as a high-level screening tool for initial risk assessment. For widespread use of TLF to be successful, standardisation of TLF values associated with different levels of risk is required, however, this study highlights the difficulties of equating TLF thresholds to TTCs or E. coli data because of the influence of DOC/HLF on the TLF signal.
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Affiliation(s)
- Jade S T Ward
- British Geological Survey, Keyworth, Nottinghamshire NG12 5GG, UK; UK Centre for Ecology & Hydrology, Wallingford OX10 8BB, UK; Department of Civil and Environmental Engineering, University of Surrey, Guildford GU2 7XH, UK.
| | | | - Daniel S Read
- UK Centre for Ecology & Hydrology, Wallingford OX10 8BB, UK
| | - Steve Pedley
- Department of Civil and Environmental Engineering, University of Surrey, Guildford GU2 7XH, UK
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14
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Ward JST, Lapworth DJ, Read DS, Pedley S, Banda ST, Monjerezi M, Gwengweya G, MacDonald AM. Large-scale survey of seasonal drinking water quality in Malawi using in situ tryptophan-like fluorescence and conventional water quality indicators. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 744:140674. [PMID: 32755770 DOI: 10.1016/j.scitotenv.2020.140674] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 06/29/2020] [Accepted: 06/30/2020] [Indexed: 06/11/2023]
Abstract
Faecally-contaminated drinking water is a risk to human health, with the greatest risks to those living in developing countries. UN Sustainable Development Goal 6 aims to address this issue. Tryptophan-like fluorescence (TLF) shows potential as a rapid method for detecting microbial contamination in drinking water, which could reduce the spread of waterborne diseases. This study is the first to investigate the effectiveness of TLF for a large-scale survey using a randomised, spot-sampling approach. The large-scale survey took place in Malawi, sub-Saharan Africa, in the dry season (n = 183). A subset of sources were revisited at the end of the following wet season (n = 41). The effectiveness of TLF was assessed by comparing TLF results to thermotolerant coliforms (TTC), humic-like fluorescence (HLF), inorganic hydrochemical data and sanitary risk scores. The most prominent differences in microbial water quality were observed between source types, with little variation between districts and seasons. TLF, TTCs, turbidity and sanitary risk scores were all elevated at alternative sources (shallow wells and tap stands) compared to hand-pumped boreholes. In the dry season, 18% of hand-pumped boreholes showed TTC contamination, which increase to 21% in the wet season. Groundwater recharge processes are likely responsible for seasonal variability of inorganic hydrochemistry at hand-pumped boreholes. TLF was able to distinguish no and low WHO risk classes (TTC 0-9 cfu/100 mL) from medium, high and very high risk classes (TTC 10 - >1000 cfu/100 mL). TLF failed to distinguish between no and low risk classes, which limits the use of TLF for assessing water quality to drinking water standards. This dataset indicates that HLF may raise baseline TLF for samples with low TLF values, increasing false positives. Therefore, TLF is better suited as a rapid high-level water quality screening tool to assess moderate and high levels of faecal contamination.
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Affiliation(s)
- Jade S T Ward
- British Geological Survey, Keyworth, Nottinghamshire NG12 5GG, UK; UK Centre for Ecology & Hydrology, Wallingford OX10 8BB, UK; Department of Civil and Environmental Engineering, University of Surrey, Guildford, GU2 7XH, UK.
| | | | - Daniel S Read
- UK Centre for Ecology & Hydrology, Wallingford OX10 8BB, UK
| | - Steve Pedley
- Department of Civil and Environmental Engineering, University of Surrey, Guildford, GU2 7XH, UK
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15
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Sorensen JPR, Diaw MT, Pouye A, Roffo R, Diongue DML, Faye SC, Gaye CB, Fox BG, Goodall T, Lapworth DJ, MacDonald AM, Read DS, Ciric L, Taylor RG. In-situ fluorescence spectroscopy indicates total bacterial abundance and dissolved organic carbon. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 738:139419. [PMID: 32521357 DOI: 10.1016/j.scitotenv.2020.139419] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/11/2020] [Accepted: 05/11/2020] [Indexed: 06/11/2023]
Abstract
We explore in-situ fluorescence spectroscopy as an instantaneous indicator of total bacterial abundance and faecal contamination in drinking water. Eighty-four samples were collected outside of the recharge season from groundwater-derived water sources in Dakar, Senegal. Samples were analysed for tryptophan-like (TLF) and humic-like (HLF) fluorescence in-situ, total bacterial cells by flow cytometry, and potential indicators of faecal contamination such as thermotolerant coliforms (TTCs), nitrate, and in a subset of 22 samples, dissolved organic carbon (DOC). Significant single-predictor linear regression models demonstrated that total bacterial cells were the most effective predictor of TLF, followed by on-site sanitation density; TTCs were not a significant predictor. An optimum multiple-predictor model of TLF incorporated total bacterial cells, nitrate, nitrite, on-site sanitation density, and sulphate (r2 0.68). HLF was similarly related to the same parameters as TLF, with total bacterial cells being the best correlated (ρs 0.64). In the subset of 22 sources, DOC clustered with TLF, HLF, and total bacterial cells, and a linear regression model demonstrated HLF was the best predictor of DOC (r2 0.84). The intergranular nature of the aquifer, timing of the study, and/or non-uniqueness of the signal to TTCs can explain the significant associations between TLF/HLF and indicators of faecal contamination such as on-site sanitation density and nutrients but not TTCs. The bacterial population that relates to TLF/HLF is likely to be a subsurface community that develops in-situ based on the availability of organic matter originating from faecal sources. In-situ fluorescence spectroscopy instantly indicates a drinking water source is impacted by faecal contamination but it remains unclear how that relates specifically to microbial risk in this setting.
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Affiliation(s)
- James P R Sorensen
- British Geological Survey, Maclean Building, Wallingford OX10 8BB, UK; Department of Geography, University College London, London WC1E 6BT, UK.
| | - Mor Talla Diaw
- Department of Geology, Université Cheikh Anta Diop, Senegal
| | | | - Raphaëlle Roffo
- Department of Geography, University College London, London WC1E 6BT, UK
| | | | | | - Cheikh B Gaye
- Department of Geology, Université Cheikh Anta Diop, Senegal
| | - Bethany G Fox
- Centre for Research in Biosciences, University of the West of England, Bristol BS16 1QY, UK
| | - Timothy Goodall
- UK Centre for Ecology & Hydrology (UKCEH), Maclean Building, Wallingford OX10 8BB, UK
| | - Daniel J Lapworth
- British Geological Survey, Maclean Building, Wallingford OX10 8BB, UK
| | - Alan M MacDonald
- British Geological Survey, Lyell Centre, Research Avenue South, Edinburgh EH14 4AP, UK
| | - Daniel S Read
- UK Centre for Ecology & Hydrology (UKCEH), Maclean Building, Wallingford OX10 8BB, UK
| | - Lena Ciric
- Department of Civil, Environmental & Geomatic Engineering, University College London, London WC1E 6BT, UK
| | - Richard G Taylor
- Department of Geography, University College London, London WC1E 6BT, UK
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16
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Sorensen JPR, Carr AF, Nayebare J, Diongue DML, Pouye A, Roffo R, Gwengweya G, Ward JST, Kanoti J, Okotto-Okotto J, van der Marel L, Ciric L, Faye SC, Gaye CB, Goodall T, Kulabako R, Lapworth DJ, MacDonald AM, Monjerezi M, Olago D, Owor M, Read DS, Taylor RG. Tryptophan-like and humic-like fluorophores are extracellular in groundwater: implications as real-time faecal indicators. Sci Rep 2020; 10:15379. [PMID: 32958794 PMCID: PMC7505957 DOI: 10.1038/s41598-020-72258-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 06/17/2020] [Indexed: 12/17/2022] Open
Abstract
Fluorescent natural organic matter at tryptophan-like (TLF) and humic-like fluorescence (HLF) peaks is associated with the presence and enumeration of faecal indicator bacteria in groundwater. We hypothesise, however, that it is predominantly extracellular material that fluoresces at these wavelengths, not bacterial cells. We quantified total (unfiltered) and extracellular (filtered at < 0.22 µm) TLF and HLF in 140 groundwater sources across a range of urban population densities in Kenya, Malawi, Senegal, and Uganda. Where changes in fluorescence occurred following filtration they were correlated with potential controlling variables. A significant reduction in TLF following filtration (ΔTLF) was observed across the entire dataset, although the majority of the signal remained and thus considered extracellular (median 96.9%). ΔTLF was only significant in more urbanised study areas where TLF was greatest. Beneath Dakar, Senegal, ΔTLF was significantly correlated to total bacterial cells (ρs 0.51). No significant change in HLF following filtration across all data indicates these fluorophores are extracellular. Our results suggest that TLF and HLF are more mobile than faecal indicator bacteria and larger pathogens in groundwater, as the predominantly extracellular fluorophores are less prone to straining. Consequently, TLF/HLF are more precautionary indicators of microbial risks than faecal indicator bacteria in groundwater-derived drinking water.
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Affiliation(s)
- James P R Sorensen
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK.
- Department of Geography, University College London, London, WC1E 6BT, UK.
| | - Andrew F Carr
- Department of Geography, University College London, London, WC1E 6BT, UK
| | - Jacintha Nayebare
- Department of Geology and Petroleum Studies, Makerere University, Kampala, Uganda
| | - Djim M L Diongue
- Department of Geology, Universite Cheikh Anta Diop, Dakar, Senegal
| | - Abdoulaye Pouye
- Department of Geology, Universite Cheikh Anta Diop, Dakar, Senegal
| | - Raphaëlle Roffo
- Department of Geography, University College London, London, WC1E 6BT, UK
| | - Gloria Gwengweya
- Chancellor College, University of Malawi, P.O. Box 280, Zomba, Malawi
| | - Jade S T Ward
- British Geological Survey, Keyworth, NG12 5GG, UK
- Department of Civil and Environmental Engineering, University of Surrey, Guildford, GU2 7XH, UK
| | - Japhet Kanoti
- Department of Geology, University of Nairobi, Nairobi, Kenya
| | - Joseph Okotto-Okotto
- Victoria Institute for Research on Environment and Development (VIRED) International, Rabuour Environment and Development Centre, Kisumu-Nairobi Road, P.O. Box, Kisumu, 6423-40103, Kenya
| | | | - Lena Ciric
- Department of Civil, Environmental and Geomatic Engineering, University College London, London, WC1E 6BT, UK
| | - Seynabou C Faye
- Department of Geology, Universite Cheikh Anta Diop, Dakar, Senegal
| | - Cheikh B Gaye
- Department of Geology, Universite Cheikh Anta Diop, Dakar, Senegal
| | - Timothy Goodall
- Centre for Ecology and Hydrology, Maclean Building, Wallingford, OX10 8BB, UK
| | - Robinah Kulabako
- Department of Civil and Environmental Engineering, Makerere University, Kampala, Uganda
| | - Daniel J Lapworth
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK
| | - Alan M MacDonald
- British Geological Survey, Lyell Centre, Research Avenue South, Edinburgh, EH14 4AP, UK
| | - Maurice Monjerezi
- Chancellor College, University of Malawi, P.O. Box 280, Zomba, Malawi
| | - Daniel Olago
- Department of Geology, University of Nairobi, Nairobi, Kenya
| | - Michael Owor
- Department of Geology and Petroleum Studies, Makerere University, Kampala, Uganda
| | - Daniel S Read
- Centre for Ecology and Hydrology, Maclean Building, Wallingford, OX10 8BB, UK
| | - Richard G Taylor
- Department of Geography, University College London, London, WC1E 6BT, UK
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17
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MacAllister DJ, MacDonald AM, Kebede S, Godfrey S, Calow R. Comparative performance of rural water supplies during drought. Nat Commun 2020; 11:1099. [PMID: 32132535 PMCID: PMC7055361 DOI: 10.1038/s41467-020-14839-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 02/07/2020] [Indexed: 11/21/2022] Open
Abstract
As rural African communities experience more frequent and extreme droughts, it is increasingly important that water supplies are climate resilient. Using a unique temporal dataset we explore rural water supply (n = 5196) performance during the 2015-16 drought in Ethiopia. Mean functionality ranged from 60% for motorised boreholes to 75% for hand-pumped boreholes. Real-time monitoring and responsive operation and maintenance led to rapid increases in functionality of hand-pumped and, to a lesser extent, motorised boreholes. Increased demand was placed on motorised boreholes in lowland areas as springs, hand-dug-wells and open sources failed. Most users travelled >1 h to access motorised boreholes but <30 min, increasing to 30-60 mins, for hand-pumped boreholes. Boreholes accessing deep (>30 m) groundwater performed best during the drought. Prioritising access to groundwater via multiple improved sources and a portfolio of technologies, such as hand-pumped and motorised boreholes, supported by responsive and proactive operation and maintenance, increases rural water supply resilience.
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Affiliation(s)
| | - A M MacDonald
- British Geological Survey, The Lyell Centre, Edinburgh, UK
| | - S Kebede
- School of Agricultural Earth and Environmental Sciences, University of KwaZulu Natal, Pietermaritzburg, South Africa
| | - S Godfrey
- UNICEF Regional Office for Eastern and Southern Africa, Nairobi, Kenya
| | - R Calow
- Overseas Development Institute, London, UK
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18
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Nakar A, Schmilovitch Z, Vaizel-Ohayon D, Kroupitski Y, Borisover M, Sela Saldinger S. Quantification of bacteria in water using PLS analysis of emission spectra of fluorescence and excitation-emission matrices. WATER RESEARCH 2020; 169:115197. [PMID: 31670087 DOI: 10.1016/j.watres.2019.115197] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 10/11/2019] [Accepted: 10/15/2019] [Indexed: 06/10/2023]
Abstract
Bacterial contamination of drinking water is a considerable concern for public health. Tryptophan-like fluorescence (TLF) has been widely suggested to enable fast and inexpensive monitoring and quantification of bacterial contamination of water. Typically, TLF is determined at a certain excitation (ex)/emission (em) wavelengths pair. The aim of this study was to assess fluorescence spectroscopy supported with partial least squares (PLS) algorithms as a tool for a rapid evaluation of the microbial quality of water, by comparing the use of a single ex/em wavelengths pair, of the spectrum of emission obtained at a single excitation wavelength to that of whole excitation-emission matrices (EEMs). For that, laboratory-grown Escherichia coli, Bacillus subtilis and Pseudomonas aeruginosa were studied as the model systems, as well as 90 groundwater samples from 6 different wells in Israel. The groundwater samples were characterized for fluorescence emission, coliforms, fecal coliforms, fecal streptococci and heterotrophic plate counts. The PLS analysis of emission spectra and, especially, of EEMs was capable of meaningfully reducing the detection limit of microorganisms in model systems, as compared with the single ex/em wavelengths pair-based determination commonly used, reaching a detection threshold as low as 10 CFU/ml. Use of PLS-analyzed EEMs becomes beneficial also in terms of correlation and similarity between the actual and predicted bacterial concentrations. Similarly, improved detection of bacteria was also achieved in groundwater samples. Furthermore, at a level of >104 CFU/ml, use of EEMs coupled with PLS enabled discrimination between E. coli, B. subtilis and P. aeruginosa.
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Affiliation(s)
- Amir Nakar
- Institute of Biochemistry and Food Science, Hebrew University of Jerusalem, Rehovot, Israel; Institute of Agricultural Engineering, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel; Department of Food Science, Institute of Postharvest and Food Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Ze'ev Schmilovitch
- Institute of Agricultural Engineering, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | | | - Yulia Kroupitski
- Department of Food Science, Institute of Postharvest and Food Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel
| | - Mikhail Borisover
- Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel.
| | - Shlomo Sela Saldinger
- Department of Food Science, Institute of Postharvest and Food Sciences, Agricultural Research Organization, Volcani Center, Rishon LeZion, Israel.
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19
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Carstea EM, Popa CL, Baker A, Bridgeman J. In situ fluorescence measurements of dissolved organic matter: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 699:134361. [PMID: 31683216 DOI: 10.1016/j.scitotenv.2019.134361] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 08/20/2019] [Accepted: 09/07/2019] [Indexed: 05/22/2023]
Abstract
There is a need for an inexpensive, reliable and fast monitoring tool to detect contaminants in a short time, for quick mitigation of pollution sources and site remediation, and for characterization of natural dissolved organic matter (DOM). Fluorescence spectroscopy has proven to be an excellent technique in quantifying aquatic DOM, from autochthonous, allochthonous or anthropogenic sources. This paper reviews the advances in in situ fluorescence measurements of DOM and pollutants in various water environments. Studies have demonstrated, using high temporal-frequency DOM fluorescence data, that marine autochthonous production of DOM is highly complex and that the allochthonous input of DOM from freshwater to marine water can be predicted. Furthermore, river measurement studies found a delayed fluorescence response of DOM following precipitation compared to turbidity and discharge, with various lags, depending on season, site and input of dissolved organic carbon (DOC) concentration. In addition, research has shown that blue light fluorescence (λemission = 430-500 nm) can be a good proxy for DOC, in environments with terrestrial inputs, and ultraviolet fluorescence (λemission = UVA-320-400 nm) for biochemical oxygen demand, and also E. coli in environments with sanitation issues. The correction of raw fluorescence data improves the relationship between fluorescence intensity and these parameters. This review also presents the specific steps and parameters that must be considered before and during in situ fluorescence measurement session for a harmonized qualitative and quantitative protocol. Finally, the strengths and weaknesses of the research on in situ fluorescence are identified.
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Affiliation(s)
- Elfrida M Carstea
- National Institute of R&D for Optoelectronics, Atomistilor 409, 077125 Magurele, Romania.
| | - Cristina L Popa
- National Institute of R&D for Optoelectronics, Atomistilor 409, 077125 Magurele, Romania.
| | - Andy Baker
- Connected Waters Initiative Research Centre, UNSW Sydney, Sydney, NSW 2052, Australia.
| | - John Bridgeman
- Faculty of Engineering and Informatics, University of Bradford, Richmond Road, Bradford BD7 1DP, UK.
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20
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Burnet JB, Sylvestre É, Jalbert J, Imbeault S, Servais P, Prévost M, Dorner S. Tracking the contribution of multiple raw and treated wastewater discharges at an urban drinking water supply using near real-time monitoring of β-d-glucuronidase activity. WATER RESEARCH 2019; 164:114869. [PMID: 31377523 DOI: 10.1016/j.watres.2019.114869] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 07/13/2019] [Accepted: 07/14/2019] [Indexed: 06/10/2023]
Abstract
Past waterborne outbreaks have demonstrated that informed vulnerability assessment of drinking water supplies is paramount for the provision of safe drinking water. Although current monitoring frameworks are not designed to account for short-term peak concentrations of fecal microorganisms in source waters, the recent development of online microbial monitoring technologies is expected to fill this knowledge gap. In this study, online near real-time monitoring of β-d-glucuronidase (GLUC) activity was conducted for 1.5 years at an urban drinking water intake impacted by multiple point sources of fecal pollution. Parallel routine and event-based monitoring of E. coli and online measurement of physico-chemistry were performed at the intake and their dynamics compared over time. GLUC activity fluctuations ranged from seasonal to hourly time scales. All peak contamination episodes occurred between late fall and early spring following intense rainfall and/or snowmelt. In the absence of rainfall, recurrent daily fluctuations in GLUC activity and culturable E. coli were observed at the intake, a pattern otherwise ignored by regulatory monitoring. Cross-correlation analysis of time series retrieved from the drinking water intake and an upstream Water Resource Recovery Facility (WRRF) demonstrated a hydraulic connection between the two sites. Sewage by-passes from the same WRRF were the main drivers of intermittent GLUC activity and E. coli peaks at the drinking water intake following intense precipitation and/or snowmelt. Near real-time monitoring of fecal pollution through GLUC activity enabled a thorough characterization of the frequency, duration and amplitude of peak contamination periods at the urban drinking water intake while providing crucial information for the identification of the dominant upstream fecal pollution sources. To the best of our knowledge, this is the first characterization of a hydraulic connection between a WRRF and a downstream drinking water intake across hourly to seasonal timescales using high frequency microbial monitoring data. Ultimately, this should help improve source water protection through catchment mitigation actions, especially in a context of de facto wastewater reuse.
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Affiliation(s)
- Jean-Baptiste Burnet
- Department of Civil, Geological, and Mining Engineering, Polytechnique Montreal, Montreal, Quebec, H3C 3A7, Canada; NSERC Industrial Chair on Drinking Water, Department of Civil, Geological, and Mining Engineering, Polytechnique Montreal, Montreal, Quebec, H3C 3A7, Canada.
| | - Émile Sylvestre
- Department of Civil, Geological, and Mining Engineering, Polytechnique Montreal, Montreal, Quebec, H3C 3A7, Canada; NSERC Industrial Chair on Drinking Water, Department of Civil, Geological, and Mining Engineering, Polytechnique Montreal, Montreal, Quebec, H3C 3A7, Canada
| | - Jonathan Jalbert
- Département de mathématiques et de génie industriel, Polytechnique Montréal, Montréal, Québec, H3C 3A7, Canada
| | - Sandra Imbeault
- Service de la Gestion de l'Eau, Ville de Laval, Quebec, H7L 2R3, Canada
| | - Pierre Servais
- Écologie des Systèmes Aquatiques, Université Libre de Bruxelles, Campus de la Plaine, Belgium
| | - Michèle Prévost
- NSERC Industrial Chair on Drinking Water, Department of Civil, Geological, and Mining Engineering, Polytechnique Montreal, Montreal, Quebec, H3C 3A7, Canada
| | - Sarah Dorner
- Department of Civil, Geological, and Mining Engineering, Polytechnique Montreal, Montreal, Quebec, H3C 3A7, Canada
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21
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Kapata N, Sinyange N, Mazaba ML, Musonda K, Hamoonga R, Kapina M, Zyambo K, Malambo W, Yard E, Riggs M, Narra R, Murphy J, Brunkard J, Azman AS, Monze N, Malama K, Mulwanda J, Mukonka VM. A Multisectoral Emergency Response Approach to a Cholera Outbreak in Zambia: October 2017-February 2018. J Infect Dis 2019; 218:S181-S183. [PMID: 30215738 PMCID: PMC6188535 DOI: 10.1093/infdis/jiy490] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Nathan Kapata
- Ministry of Health, Lusaka, Zambia.,Zambia National Public Health Institute, Lusaka
| | - Nyambe Sinyange
- Ministry of Health, Lusaka, Zambia.,Zambia National Public Health Institute, Lusaka.,Zambia Field Epidemiology Training Program, Lusaka
| | - Mazyanga Lucy Mazaba
- Ministry of Health, Lusaka, Zambia.,Zambia National Public Health Institute, Lusaka
| | - Kunda Musonda
- Ministry of Health, Lusaka, Zambia.,Zambia National Public Health Institute, Lusaka
| | - Raymond Hamoonga
- Ministry of Health, Lusaka, Zambia.,Zambia National Public Health Institute, Lusaka
| | - Muzala Kapina
- Ministry of Health, Lusaka, Zambia.,Zambia National Public Health Institute, Lusaka
| | | | - Warren Malambo
- US Centers for Disease Control and Prevention, Lusaka, Zambia
| | - Ellen Yard
- US Centers for Disease Control and Prevention, Lusaka, Zambia
| | - Margaret Riggs
- US Centers for Disease Control and Prevention, Lusaka, Zambia
| | - Rupa Narra
- US Centers for Disease Control and Prevention, Lusaka, Zambia
| | - Jennifer Murphy
- US Centers for Disease Control and Prevention, Lusaka, Zambia
| | - Joan Brunkard
- US Centers for Disease Control and Prevention, Lusaka, Zambia
| | - Andrew S Azman
- Médecins Sans Frontières, Geneva, Switzerland.,Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | | | | | | | - Victor M Mukonka
- Ministry of Health, Lusaka, Zambia.,Zambia National Public Health Institute, Lusaka.,Copperbelt University, School of Medicine, Ndola, Zambia
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22
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Tsai K, Simiyu S, Mumma J, Aseyo RE, Cumming O, Dreibelbis R, Baker KK. Enteric Pathogen Diversity in Infant Foods in Low-Income Neighborhoods of Kisumu, Kenya. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16030506. [PMID: 30759722 PMCID: PMC6388216 DOI: 10.3390/ijerph16030506] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 02/05/2019] [Accepted: 02/07/2019] [Indexed: 01/01/2023]
Abstract
Pediatric diarrheal disease remains the second most common cause of preventable illness and death among children under the age of five, especially in low and middle-income countries (LMICs). However, there is limited information regarding the role of food in pathogen transmission in LMICs. For this study, we examined the frequency of enteric pathogen occurrence and co-occurrence in 127 infant weaning foods in Kisumu, Kenya, using a multi-pathogen PCR diagnostic tool, and assessed household food hygiene risk factors for contamination. Bacterial, viral, and protozoan enteric pathogen DNA and RNA were detected in 62% of the infant weaning food samples collected, with 37% of foods containing more than one pathogen type. Multivariable generalized linear mixed model analysis indicated type of infant food best explained the presence and diversity of enteric pathogens in infant food, while most household food hygiene risk factors considered in this study were not significantly associated with pathogen contamination. Specifically, cow’s milk was significantly more likely to contain a pathogen (adjusted risk ratio = 14.4; 95% confidence interval (CI) 1.78–116.1) and more likely to have higher number of enteric pathogen species (adjusted risk ratio = 2.35; 95% CI 1.67–3.29) than porridge. Our study demonstrates that infants in this low-income urban setting are frequently exposed to diarrhoeagenic pathogens in food and suggests that interventions are needed to prevent foodborne transmission of pathogens to infants.
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Affiliation(s)
- Kevin Tsai
- Department of Occupational and Environmental Health, University of Iowa, Iowa City, IA 52246, USA.
| | - Sheillah Simiyu
- Center of Research, Great Lakes University of Kisumu, Kisumu 40100, Kenya.
| | - Jane Mumma
- Center of Research, Great Lakes University of Kisumu, Kisumu 40100, Kenya.
| | - Rose Evalyne Aseyo
- Center of Research, Great Lakes University of Kisumu, Kisumu 40100, Kenya.
| | - Oliver Cumming
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK.
| | - Robert Dreibelbis
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK.
| | - Kelly K Baker
- Department of Occupational and Environmental Health, University of Iowa, Iowa City, IA 52246, USA.
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23
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Nowicki S, Lapworth DJ, Ward JST, Thomson P, Charles K. Tryptophan-like fluorescence as a measure of microbial contamination risk in groundwater. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 646:782-791. [PMID: 30064104 DOI: 10.1016/j.scitotenv.2018.07.274] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 07/19/2018] [Accepted: 07/19/2018] [Indexed: 06/08/2023]
Abstract
Microbial water quality is frequently assessed with a risk indicator approach that relies on Escherichia coli. Relying exclusively on E. coli is limiting, particularly in low-resource settings, and we argue that risk assessments could be improved by a complementary parameter, tryptophan-like fluorescence (TLF). Over two campaigns (June 2016 and March 2017) we sampled 37 water points in rural Kwale County, Kenya for TLF, E. coli and thermotolerant coliforms (total n = 1082). Using three World Health Organization defined classes (very high, high, and low/intermediate), risk indicated by TLF was not significantly different from risk indicated by E. coli (p = 0.85). However, the TLF and E. coli risk classifications did show disagreement, with TLF indicating higher risk for 14% of samples and lower risk for 13% of samples. Comparisons of duplicate/replicate results demonstrated that precision is higher for TLF (average relative percent difference of duplicates = 14%) compared to culture-based methods (average RPD of duplicates ≥ 26%). Additionally, TLF sampling is more practical because it requires less time and resources. Precision and practicality make TLF well-suited to high-frequency sampling in low resource contexts. Interpretation and interference challenges are minimised when TLF is measured in groundwaters, which typically have low dissolved organic carbon, relatively consistent temperature, negligible turbidity and pH between 5 and 8. TLF cannot be used as a proxy for E. coli on an individual sample basis, but it can add value to groundwater risk assessments by improving prioritization of sampling and by increasing understanding of spatiotemporal variability.
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Affiliation(s)
- Saskia Nowicki
- University of Oxford, School of Geography and the Environment, Oxford OX1 3QY, UK.
| | - Dan J Lapworth
- British Geological Survey, Maclean Building, Wallingford OX10 8BB, UK
| | - Jade S T Ward
- British Geological Survey, Maclean Building, Wallingford OX10 8BB, UK; University of Surrey, Department of Civil and Environmental Engineering, Guildford GU2 7XH, UK
| | - Patrick Thomson
- University of Oxford, School of Geography and the Environment, Oxford OX1 3QY, UK
| | - Katrina Charles
- University of Oxford, School of Geography and the Environment, Oxford OX1 3QY, UK
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24
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Microbial Processing and Production of Aquatic Fluorescent Organic Matter in a Model Freshwater System. WATER 2018. [DOI: 10.3390/w11010010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Organic matter (OM) has an essential biogeochemical influence along the hydrological continuum and within aquatic ecosystems. Organic matter derived via microbial processes was investigated within a range of model freshwater samples over a 10-day period. For this, excitation-emission matrix (EEM) fluorescence spectroscopy in combination with parallel factor (PARAFAC) analysis was employed. This research shows the origin and processing of both protein-like and humic-like fluorescence within environmental and synthetic samples over the sampling period. The microbial origin of Peak T fluorescence is demonstrated within both synthetic samples and in environmental samples. Using a range of incubation temperatures provides evidence for the microbial metabolic origin of Peak T fluorescence. From temporally resolved experiments, evidence is provided that Peak T fluorescence is an indication of metabolic activity at the microbial community level and not a proxy for bacterial enumeration. This data also reveals that humic-like fluorescence can be microbially derived in situ and is not solely of terrestrial origin, likely to result from the upregulation of cellular processes prior to cell multiplication. This work provides evidence that freshwater microbes can engineer fluorescent OM, demonstrating that microbial communities not only process, but also transform, fluorescent organic matter.
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25
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Sorensen JPR, Baker A, Cumberland SA, Lapworth DJ, MacDonald AM, Pedley S, Taylor RG, Ward JST. Real-time detection of faecally contaminated drinking water with tryptophan-like fluorescence: defining threshold values. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 622-623:1250-1257. [PMID: 29890592 DOI: 10.1016/j.scitotenv.2017.11.162] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 11/14/2017] [Accepted: 11/15/2017] [Indexed: 06/08/2023]
Abstract
We assess the use of fluorescent dissolved organic matter at excitation-emission wavelengths of 280nm and 360nm, termed tryptophan-like fluorescence (TLF), as an indicator of faecally contaminated drinking water. A significant logistic regression model was developed using TLF as a predictor of thermotolerant coliforms (TTCs) using data from groundwater- and surface water-derived drinking water sources in India, Malawi, South Africa and Zambia. A TLF threshold of 1.3ppb dissolved tryptophan was selected to classify TTC contamination. Validation of the TLF threshold indicated a false-negative error rate of 15% and a false-positive error rate of 18%. The threshold was unsuccessful at classifying contaminated sources containing <10 TTC cfu per 100mL, which we consider the current limit of detection. If only sources above this limit were classified, the false-negative error rate was very low at 4%. TLF intensity was very strongly correlated with TTC concentration (ρs=0.80). A higher threshold of 6.9ppb dissolved tryptophan is proposed to indicate heavily contaminated sources (≥100 TTC cfu per 100mL). Current commercially available fluorimeters are easy-to-use, suitable for use online and in remote environments, require neither reagents nor consumables, and crucially provide an instantaneous reading. TLF measurements are not appreciably impaired by common intereferents, such as pH, turbidity and temperature, within typical natural ranges. The technology is a viable option for the real-time screening of faecally contaminated drinking water globally.
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Affiliation(s)
| | - Andy Baker
- Connected Waters Initiative Research Centre, UNSW Australia, Sydney, New South Wales 2052, Australia
| | | | - Dan J Lapworth
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK
| | | | - Steve Pedley
- Department of Civil and Environmental Engineering, University of Surrey, Guildford GU2 7XH, UK
| | - Richard G Taylor
- Department of Geography, University College London, London WC1E 6BT, UK
| | - Jade S T Ward
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK; Department of Civil and Environmental Engineering, University of Surrey, Guildford GU2 7XH, UK
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26
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Mbaka PK, Mwangi JK, Kiptum CK. Assessment of water quality in selected shallow wells of Keiyo Highlands, Kenya. AFRICAN JOURNAL OF SCIENCE, TECHNOLOGY, INNOVATION AND DEVELOPMENT 2017. [DOI: 10.1080/20421338.2017.1327476] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Peter K. Mbaka
- Department of Civil, Construction and Environmental Engineering, Jomo Kenyatta University of Agriculture and Technology, Kenya
| | - John K. Mwangi
- Department of Civil, Construction and Environmental Engineering, Jomo Kenyatta University of Agriculture and Technology, Kenya
| | - Clement K. Kiptum
- Department of Civil and Structural Engineering, University of Eldoret, Kenya
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27
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Lapworth DJ, Nkhuwa DCW, Okotto-Okotto J, Pedley S, Stuart ME, Tijani MN, Wright J. Urban groundwater quality in sub-Saharan Africa: current status and implications for water security and public health. HYDROGEOLOGY JOURNAL 2017; 25:1093-1116. [PMID: 32055234 PMCID: PMC6991975 DOI: 10.1007/s10040-016-1516-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Accepted: 12/06/2016] [Indexed: 05/18/2023]
Abstract
Groundwater resources are important sources of drinking water in Africa, and they are hugely important in sustaining urban livelihoods and supporting a diverse range of commercial and agricultural activities. Groundwater has an important role in improving health in sub-Saharan Africa (SSA). An estimated 250 million people (40% of the total) live in urban centres across SSA. SSA has experienced a rapid expansion in urban populations since the 1950s, with increased population densities as well as expanding geographical coverage. Estimates suggest that the urban population in SSA will double between 2000 and 2030. The quality status of shallow urban groundwater resources is often very poor due to inadequate waste management and source protection, and poses a significant health risk to users, while deeper borehole sources often provide an important source of good quality drinking water. Given the growth in future demand from this finite resource, as well as potential changes in future climate in this region, a detailed understanding of both water quantity and quality is required to use this resource sustainably. This paper provides a comprehensive assessment of the water quality status, both microbial and chemical, of urban groundwater in SSA across a range of hydrogeological terrains and different groundwater point types. Lower storage basement terrains, which underlie a significant proportion of urban centres in SSA, are particularly vulnerable to contamination. The relationship between mean nitrate concentration and intrinsic aquifer pollution risk is assessed for urban centres across SSA. Current knowledge gaps are identified and future research needs highlighted.
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Affiliation(s)
- D. J. Lapworth
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB UK
| | - D. C. W. Nkhuwa
- University of Zambia, Great East Road Campus, P.O. Box 32379, Lusaka, Zambia
| | - J. Okotto-Okotto
- Victoria Institute for Research on Environment and Development (VIRED) International, Rabuour Environment and Development Centre, Kisumu-Nairobi Road, P.O. Box 6423-40103, Kisumu, Kenya
| | - S. Pedley
- Robens Centre for Public and Environmental Health, University of Surrey, Guildford, GU2 7XH UK
| | - M. E. Stuart
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB UK
| | - M. N. Tijani
- Department of Geology, University of Ibadan, Ibadan, Oyo State Nigeria
| | - J. Wright
- Geography and Environment, University of Southampton, Highfield, Southampton, SO17 1BJ UK
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28
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Duan C, Cui Y, Zhao Y, Zhai J, Zhang B, Zhang K, Sun D, Chen H. Evaluation of Faecalibacterium 16S rDNA genetic markers for accurate identification of swine faecal waste by quantitative PCR. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2016; 181:193-200. [PMID: 27353369 DOI: 10.1016/j.jenvman.2016.06.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 06/16/2016] [Accepted: 06/17/2016] [Indexed: 06/06/2023]
Abstract
A genetic marker within the 16S rRNA gene of Faecalibacterium was identified for use in a quantitative PCR (qPCR) assay to detect swine faecal contamination in water. A total of 146,038 bacterial sequences were obtained using 454 pyrosequencing. By comparative bioinformatics analysis of Faecalibacterium sequences with those of numerous swine and other animal species, swine-specific Faecalibacterium 16S rRNA gene sequences were identified and Polymerase Chain Okabe (PCR) primer sets designed and tested against faecal DNA samples from swine and non-swine sources. Two PCR primer sets, PFB-1 and PFB-2, showed the highest specificity to swine faecal waste and had no cross-reaction with other animal samples. PFB-1 and PFB-2 amplified 16S rRNA gene sequences from 50 samples of swine with positive ratios of 86 and 90%, respectively. We compared swine-specific Faecalibacterium qPCR assays for the purpose of quantifying the newly identified markers. The quantification limits (LOQs) of PFB-1 and PFB-2 markers in environmental water were 6.5 and 2.9 copies per 100 ml, respectively. Of the swine-associated assays tested, PFB-2 was more sensitive in detecting the swine faecal waste and quantifying the microbial load. Furthermore, the microbial abundance and diversity of the microbiomes of swine and other animal faeces were estimated using operational taxonomic units (OTUs). The species specificity was demonstrated for the microbial populations present in various animal faeces.
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Affiliation(s)
- Chuanren Duan
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400044, PR China.
| | - Yamin Cui
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400044, PR China
| | - Yi Zhao
- Key Laboratory of Drug Targeting and Drug Delivery System of Education Ministry, Department of Medicinal Chemistry, West China School of Pharmacy, Sichuan University, Chengdu, 610041, PR China
| | - Jun Zhai
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, College of Urban Construction and Environmental Engineering, Chongqing University, Chongqing, 400045, PR China.
| | - Baoyun Zhang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400044, PR China
| | - Kun Zhang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400044, PR China
| | - Da Sun
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400044, PR China
| | - Hang Chen
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400044, PR China
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29
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Li WT, Jin J, Li Q, Wu CF, Lu H, Zhou Q, Li AM. Developing LED UV fluorescence sensors for online monitoring DOM and predicting DBPs formation potential during water treatment. WATER RESEARCH 2016; 93:1-9. [PMID: 26874469 DOI: 10.1016/j.watres.2016.01.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Revised: 12/18/2015] [Accepted: 01/04/2016] [Indexed: 06/05/2023]
Abstract
Online monitoring dissolved organic matter (DOM) is urgent for water treatment management. In this study, high performance size exclusion chromatography with multi-UV absorbance and multi-emission fluorescence scans were applied to spectrally characterize samples from 16 drinking water sources across Yangzi River and Huai River Watersheds. The UV absorbance indices at 254 nm and 280 nm referred to the same DOM components and concentration, and the 280 nm UV light could excite both protein-like and humic-like fluorescence. Hence a novel UV fluorescence sensor was developed out using only one UV280 light-emitting diode (LED) as light source. For all samples, enhanced coagulation was mainly effective for large molecular weight biopolymers; while anion exchange further substantially removed humic substances. During chlorination tests, UVA280 and UVA254 showed similar correlations with yields of disinfection byproducts (DBPs); the humic-like fluorescence obtained from LED sensors correlated well with both trihalomethanes and haloacetic acids yields, while the correlation between protein-like fluorescence and trihalomethanes was relatively poor. Anion exchange exhibited more reduction of DBPs yields as well as UV absorbance and fluorescence signals than enhanced coagulation. The results suggest that the LED UV fluorescence sensors are very promising for online monitoring DOM and predicting DBPs formation potential during water treatment.
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Affiliation(s)
- Wen-Tao Li
- State Key Laboratory of Pollution Control and Resources Reuse, Collaborative Innovation Center for Advanced Water Pollution Control Technology and Equipment, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Jing Jin
- State Key Laboratory of Pollution Control and Resources Reuse, Collaborative Innovation Center for Advanced Water Pollution Control Technology and Equipment, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Qiang Li
- State Key Laboratory of Pollution Control and Resources Reuse, Collaborative Innovation Center for Advanced Water Pollution Control Technology and Equipment, School of the Environment, Nanjing University, Nanjing, 210023, China
| | - Chen-Fei Wu
- Jiangsu Provincial Key Lab of Advanced Photon & Electronic Material, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210023, China
| | - Hai Lu
- Jiangsu Provincial Key Lab of Advanced Photon & Electronic Material, School of Electronic Science and Engineering, Nanjing University, Nanjing, 210023, China
| | - Qing Zhou
- State Key Laboratory of Pollution Control and Resources Reuse, Collaborative Innovation Center for Advanced Water Pollution Control Technology and Equipment, School of the Environment, Nanjing University, Nanjing, 210023, China.
| | - Ai-Min Li
- State Key Laboratory of Pollution Control and Resources Reuse, Collaborative Innovation Center for Advanced Water Pollution Control Technology and Equipment, School of the Environment, Nanjing University, Nanjing, 210023, China.
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30
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Sorensen JPR, Sadhu A, Sampath G, Sugden S, Dutta Gupta S, Lapworth DJ, Marchant BP, Pedley S. Are sanitation interventions a threat to drinking water supplies in rural India? An application of tryptophan-like fluorescence. WATER RESEARCH 2016; 88:923-932. [PMID: 26618806 DOI: 10.1016/j.watres.2015.11.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 10/27/2015] [Accepted: 11/02/2015] [Indexed: 05/04/2023]
Abstract
Open defecation is practised by over 600 million people in India and there is a strong political drive to eliminate this through the provision of on-site sanitation in rural areas. However, there are concerns that the subsequent leaching of excreta from subsurface storage could be adversely impacting underlying groundwater resources upon which rural populations are almost completely dependent for domestic water supply. We investigated this link in four villages undergoing sanitary interventions in Bihar State, India. A total of 150 supplies were sampled for thermotolerant (faecal) coliforms (TTC) and tryptophan-like fluorescence (TLF): an emerging real-time indicator of faecal contamination. Sanitary risk inspections were also performed at all sites, including whether a supply was located within 10 m of a toilet, the recommended minimum separation. Overall, 18% of water supplies contained TTCs, 91% of which were located within 10 m of a toilet, 58% had TLF above detection limit, and sanitary risk scores were high. Statistical analysis demonstrated TLF was an effective indicator of TTC presence-absence, with a possibility of TTCs only where TLF exceeded 0.4 μg/L dissolved tryptophan. Analysis also indicated proximity to a toilet was the only significant sanitary risk factor predicting TTC presence-absence and the most significant predictor of TLF. Faecal contamination was considered a result of individual water supply vulnerability rather than indicative of widespread leaching into the aquifer. Therefore, increasing faecal contamination of groundwater-derived potable supplies is inevitable across the country as uptake of on-site sanitation intensifies. Communities need to be aware of this link and implement suitable decentralised low-cost treatment of water prior to consumption and improve the construction and protection of new supplies.
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Affiliation(s)
- J P R Sorensen
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK.
| | - A Sadhu
- Water For People, India Country Office, M-18, First Floor, Green Park Extension, New Delhi, India
| | - G Sampath
- Water For People, India Country Office, M-18, First Floor, Green Park Extension, New Delhi, India
| | - S Sugden
- Water For People, Wallingford, UK
| | - S Dutta Gupta
- School of Environmental Science and Engineering, Indian Institute of Technology (IIT), Kharagpur, India
| | - D J Lapworth
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK
| | - B P Marchant
- British Geological Survey, Nicker Hill, Keyworth, Nottingham, NG12 5GG, UK
| | - S Pedley
- Department of Civil and Environmental Engineering, University of Surrey, Guildford, GU2 7XH, UK
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